This invention relates to irrigation sprinklers, and more particularly to a new and improved adjustable oscillating wave-type sprinkler primarily intended for use in irrigating lawns, flowers, shrubs, and the like.
Oscillating wave-type sprinklers have long been known and used in the irrigation field for watering lawns, gardens, shrubs, flowers, and other plants. Typically, such sprinklers include a water-driven motor mounted in a housing and which drives an elongated spray tube for side-to-side oscillation of about a generally horizontal axis. The spray tube, which usually is formed of thin gauge tubular material, has a plurality of water outlet openings or nozzles spaced along the length of the tube and disposed to project discreet water streams outwardly from the tube in a fan or wave-like spray pattern. As the spray tube oscillates about its axis, the fan-like spray produced by the outlets or nozzles translates back and forth across the ground producing a general rain-like fall out to either side of the sprinkler.
Typically, the water-driven motor employed in conventional oscillating wave-type sprinklers have included water driven turbines or impellers coupled to the spray tube through reduction gearing and linkage mechanisms. Through use of cams and/or linkage adjustment, the back and forth oscillation of the spray tube has been controlled so that the spray tube will oscillate substantially uniformly back and forth over the ground area to be irrigated. Exemplary of such prior art oscillating wave-type sprinklers are those marketed by Rain Bird Sprinkler Mfg. Corp. of Glendora, Calif. as, for example, depicted at page 5 of its 1989 Rain Bird Consumer Products Catalog.
One problem inherent in most oscillating wave-type sprinklers is that the distribution pattern of water over the ground tends to be confined to discreet narrow strips or bands formed on each side of the spray tube where the individual water sprays from each outlet or nozzle regularly fall to the ground. One effort to solve this problem which has met with significant commercial success has been the oscillating wave-type sprinklers manufactured by Rain Bird Sprinkler Mfg. Corp. in accordance with U.S. Pat. No. 4,860,954 issued Aug. 29, 1989 and entitled ADJUSTABLE OSCILLATING WAVE-TYPE SPRINKLER. That patent illustrates and describes an oscillating wave-type sprinkler employing a conventional water-driven motor for oscillating an elongated spray tube, and which includes a throttling mechanism for cyclically throttling the water flow to the spray tube so that the spray pattern from each nozzle cyclically moves radially inwardly and outwardly relative to the spray tube. This has been found to enhance the uniformity of water distribution pattern so as to not leave unwatered or underwatered strips along the length of the fan-shape spray as the spray tube oscillates.
Another problem inherent in most oscillating wave-type sprinklers is that the spray pattern produced does not result in well defined corners so that the pattern is rounded rather than more rectangular, as is desirable for oscillating wave-type sprinkler uses. A still further problem encountered by many prior art oscillating wave-type sprinklers is that of over watering at the extremes of the oscillating spray pattern during reversal of the direction of spray tube rotation. Prior art attempts at overcoming this problem have included the use of heart shaped cams and other linkage mechanisms to attempt to accelerate the speed of rotation during spray tube direction transition. Exemplary of oscillating sprinkler mechanisms of this type is that disclosed in U.S. Pat. No. 3,261,553 issued to Kooi et al July 19, 1966 entitled OSCILLATING LAWN SPRINKLER.
Still further problems inherent in many prior art oscillating wave-type sprinklers is that the water driven turbines or impellers rotate at very high speeds which necessitate the use of reduction gearing to control the rate of spray tube oscillation, thereby adding to the cost of manufacture and assembly, and reducing efficiency of operation.
Thus, there exists a need for a new and improved oscillating wave-type sprinkler which is capable of producing a precise rectangular spray pattern of various sizes, and which will uniformly apply irrigating water over the entire area irrigated. As will become more apparent from the following, the present invention meets this need in a novel and unobvious manner.